Such systems and methods (as described f.i. in European Patent Application 07112664.3) for processing light in a structure, f.i. a room or a part thereof, a lobby, a vehicle, etc., typically include the arrangement of several light sources in the structure. The light sources emit light carrying individual codes, identifying the light source. Arranging a camera in a camera-position of the structure and registering images of spots of the light allows through the identification of the individual codes which light source contributes to an illumination pattern. The spots can be, for instance, illuminated areas on a floor, a wall, or ceiling. The image may even include the direct light images of a light source. Besides deriving the individual codes from the registered images, a signal processing apparatus can also determine one or more properties (such as for instance light source position, light intensity, color point, etc) related to the associated light source. A typical application of the system and method is light effect commissioning and real time foot-print measurements.
As the light modulations necessary to incorporate the light source identification codes typically are well over 1000 Hz (allowing both invisibility to the human eye and a large bandwidth for data transfer), the known system needs to incorporate a high speed camera to distinguish the codes and consequently the footprints of the different light sources in the illumination system. This results in a high cost solution.